Method of and device for filling bags, having a movable filling sleeve

ABSTRACT

A method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve  16  connected to a filling cone  15  and filled with a measured quantity of bulk material. For closing purposes, the bags, after having been filled, are folded-in at the bag flap in a bag flap folding device  20  and, after having been closed, are gripped by a takeover device  26  for the purpose of being transported further. The filling sleeve during or after the operation of filling a suspended bag and the bag flap folding device during or after the operation of folding an attached bag are synchronously moved in a bag transporting direction at a fixed distance from a respective starting position P 1 , P 2  by the amount of the distance x1 between the filling sleeve and the bag flap folding device  20  into a respective hand-over position P 2 , P 3 . The takeover device  26 , during the synchronous movement of the filling sleeve  16  and the bag folding device  20 , is moved from a starting position P 3  into a releasing position P 4  for the purpose of transporting further a folded-in bag.

FIELD OF INVENTION

[0001] The invention relates to a method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve connected to a filling cone and filled with a measured quantity of bulk material. For closing purposes, the bags, after having been filled, are folded-in at the bag flap in a bag flap folding device and, after having been closed, are gripped by a take-over device for the purpose of being transported further. This invention also relates to a device for filling bags with bulk material and for closing the filled bags, wherein there are provided a filling sleeve for attaching a bag, which filling sleeve is connected to a filling cone, a bag flap folding device for folding-in the bag flap of a bag and a take-over device for further transport of a bag after the folding-in operation. Furthermore, the invention relates to a bag flap folding device as it can be preferably used in the above-mentioned device for filling the bags.

BACKGROUND OF THE INVENTION

[0002] A method and a device of the initially mentioned type are described in the an earlier unpublished application DE 100 52 839.2. The purpose of this device is to fill bags at an increased filling frequency as compared to prior art filling devices. In such prior art filling devices, the filling sleeve is fixed and the filled bag cannot be deposited from the filling sleeve and transported further until, in a folding device arranged at a fixed distance from the filling sleeve, another bag is finish-folded and ready to be transported further. In accordance with the earlier application, the filling frequency is increased in that, by horizontally transporting the filling sleeve and horizontally transporting a take-over device in the opposite direction, bags suspended from the filling sleeve and the take-over device respectively are transported in a hanging position to the bag flap folding device. In this way it is possible to carry out the filling process while the horizontal bag transport has already started. In any case, the filling sleeve and the take-over device move oscillatingly in opposition directions, with each of the units covering a distance of half the amount of the distance between the filling sleeve and the bag flap folding device. The bag flap folding device moves at a constant distance synchronously with the filling sleeve without the bag transport between the filling sleeve and the folding device being affected. The take-over device takes over the bag which is still suspended from the filling sleeve and does not deposit it until the filling sleeve and the take-over device have reached a position in which they are furthest removed from one another and which corresponds to the fixed distance between the filling sleeve and the bag flap folding device. A method and a device of said type improve the transporting performance, but the method of transferring the bags from the filling sleeve to the folding device has been found to be complicated and easily subject to interference.

OBJECT OF THE INVENTION

[0003] It is therefore the object of the present invention to provide a device of said species which increases the filling performance relative to a device according to the state of the art and which, as compared to the device according to the earlier application, is designed more simply and, in operation, is less likely to be subject to interference.

SUMMARY OF THE INVENTION

[0004] The objective is achieved by providing a method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve connected to a filling cone and filled with a measured quantity of bulk material and wherein, for closing purposes, the bags, after having been filled, are folded-in at the bag flap in a bag flap folding device and, after having been closed, are gripped by take-over device for the purpose of being transported further.

[0005] The filling sleeve, during or after the operation of filling a suspended bag, and the bag flag folding device, during or after the operation of folding-in an attached bag, are synchronously moved in a bag transporting direction at a fixed distance from a respective starting position P1, P2 by the amount of the distance x1 between the filling sleeve and the bag flap folding device into a respective hand-over position P2, P3. Here the respective bags are released by the filling sleeve and the bag flap folding device respectively, whereupon the filling sleeve and the bag flap folding device are returned synchronously at a fixed distance against the bag transporting direction into their respective starting positions P1 P2. Furthermore, the solution consists in providing a device for filling bags with bulk material and for closing the filled bags, wherein there are provided a filling sleeve for attaching a bag, which filling sleeve is connected to a filling cone, a bag flap folding device for folding-in the bag flap of a bag and a take-over device for further transport of a bag after the folding-in operation. The filling sleeve and the bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance x1 between the filling sleeve and the bag flap folding device between two respective starting positions P1, P2, and two respective hand-over positions P2, P3.

[0006] An advantageous further embodiment consists in that the take-over device is movable between a starting position P3, and a releasing position P4 which is at the same distance x1=x2 from the starting position P2 of the bag flap folding device as is the latter in its starting position P2 from the starting position P1 of the filling sleeve. The releasing position P4 is in the same phase in the bag transporting direction and against the bag transporting direction as are the filling sleeve and the bag flap folding device.

[0007] A further solution consists in a method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve connected to a filling cone and filled with a measured quantity of bulk material. For closing purposes, the bags, after having been filled, are folded-in at the bag flap in a bag flap folding device and, after having been closed, are gripped by a take-over device for the purpose of being transported further. The first filling sleeve during or after the operation of filling a suspended bag and the first bag flap folding device during or after the operation of folding-in attached bag are synchronously moved in a first bag transporting direction R1 at a fixed distance from a respective starting position P1′, P2′ by the amount of the distance x1 between a first filling sleeve and a first bag flap folding device into a respective hand-over position P2′, P3 wherein the respective bag is released by the filling sleeve and the bag flap folding device respectively. Than the first filling sleeve and the first bag flap folding device are returned synchronously at a fixed distance against the first bag transporting direction R1 into their respective starting positions P1′, P2′. At the same time, after the release of the respective bags, a second filling sleeve and a second bag flap folding device are moved synchronously at a fixed distance from one another by the mount of the distance x1 of the second filling sleeve from the second bag flap folding device into a respective starting position P1″, P2″. Here a bag slipped on to the filling sleeve is filled and where, respectively, a bag positioned in the bag flap folding device is folded-in, whereupon the second filling sleeve and the second bag flap folding device are returned synchronously in the second bag transporting direction R2 into their hand-over positions P2″, P3″.

[0008] A corresponding device for filling bags with bulk material and for closing the filled bags comprises a first filling sleeve for attaching a bag, which first filling sleeve is connected to a filling cone. A first bag flap folding device is provided for folding-in the bag flap of a bag, as is a take-over device for further transport of a bag after the folding-in operation. The first filling sleeve and the first bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance x1 between the first filling sleeve and the first bag flap folding device between two respective starting positions P1′, P2′ and two respective hand-over positions P2′, P3′. This device further comprises a second filling sleeve connected to a filling cone and provided for attaching a bag, a second bag flap folding device for folding-in the bag flap of a bag and a second take-over device for further transport of a bag after having been folded-in. The second filling sleeve and the second bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance between the second filling sleeve and the second bag flap folding device and synchronously with the two former in the same respective direction between two respective hand-over positions P2″, P3″ and two respective starting positions P1″, P2″.

[0009] An advantageous further embodiment consists in that a first take-over device is movable between a starting position P3′ and a releasing position P4 ′, which is at the same distance x2=x1 from the starting position P2′ of the first bag flap folding device as is the latter in its starting position P2′ from the starting position P1′ of the first filling sleeve. This takes place in the same phase in the first bag transporting direction and against the first bag transporting direction as the first filling sleeve and the first bag flap folding device. A second take-over device is movable between a starting position P3″ and a releasing position P4″, which is at the same distance x2=x1 from the starting position P2″ of the second bag flap folding device as is the latter in its starting position P2″ from the starting position of P1′ of the second filling sleeve. This takes place' in the same phase in the second bag transporting direction and against the second bag transporting direction as the second filling sleeve and the second bag flap folding device. The take-over devices being movable in corresponding directions. According to a first alternative, the take-over device comprises a sealing unit, especially a welding unit. According to a second alternative, the take-over device is followed by a sealing unit in the bag transporting direction.

[0010] In accordance with the principle on which the invention is based, the entire bag transport from the filling sleeve into the bag flap folding device is carried out as a result of the movement of the bag suspended from the filling sleeve which does not release the bag until it has reached a position in which it can be handled directly by the bag flap folding device without having to be transported any further in the horizontal direction. The bag flap folding device preferably moves at a constant distance synchronously with the filling sleeve. This is greatly advantageous in that the bag, without being obstructed, can be moved with the filling sleeve into the position in which it is subsequently received and handled by the bag flap folding device.

[0011] According to a further preferred embodiment, it is proposed that the takeover device also moves oscillatingly in the bag transporting direction synchronously with the filling sleeve and the bag flap folding device which is able to receive the deposited bag which, during the counter movement of the filling sleeve and the bag flap folding device against the bag transporting direction, had been released by the folding device with the bag flap in a folded-in condition. The bag flap folding device then moves the bag into a subsequent position from which it is transported further. In an advantageous embodiment, the take-over device can be provided with sealing device which seals the folded bag at the bag flap, i.e. it either welds or glues or sews the bag for example. However, it is also possible to include a sealing device in the transport path following the take-over device in the bag transporting direction. To prevent the bag which has already been folded-in by said bag flap folding device from opening after having been released and up to the point of being gripped by the take-over device, there is preferably provided a fixing device which is able, temporarily, to fix, by means of clamps, the folded-in bag flap. In particular, the fixing device has to be stationary in the bag transporting direction and its height must be adjustable. In accordance with the solution mentioned first, the inventive device can be designed in such a way that there is provided only one of each assembly mentioned, as a result of which there is obtained one single bag transporting direction. According to the other solution referred to, it is possible to combine one single dispensing device with the remaining assemblies of each of which there are provided two and which are arranged symmetrically, with the functions of the two symmetric assemblies being offset relative to one another by half a phase. In such a case, the bags are filled alternately by the two different filling sleeves and moved away in an attached form for further handing in opposed bag transporting directions.

[0012] Furthermore, the invention provides a particularly suitable bag flap folding device for open bags filled with a filling material and- having a substantially rectangular cross-section with two opposed first bag walls and two further opposed second bag walls. This bag flap folding device is characterized by two folding flaps which, in a starting position, can be made to rest against the first bag walls in a planar way and which can be pivoted around horizontal axes into a folding position in which they place the contacting first bag walls in a planar way substantially horizontally on the surface of the filling material, with the bag flap projecting upwardly in a flat condition beyond the abutting end faces of the folding flaps. Such a device is particularly suitable for folding-in bags with side folds particularly quickly and in an interference-free way, which bags are then sealed at the bag flap. The folding flaps can comprise suction pads which suck up the first bag walls. According to a special embodiment, it is proposed that the folding flaps, together with the first side walls contacting one another in a planar way on the inside can be stopped in an intermediate position in which they are inclined relative to one another in a roof-like way. Furthermore, there is provided a side fold forming device with two side fold forming blades which, in a starting position, are positioned at a distance outside the tensioned second side walls and which, in a side fold forming position, are positioned between the suction pads in the intermediate position of same. The side fold forming device can be moved up and down. Furthermore, there is provided a fixing device which comprises clamping means which are able to fix, by means of clamps, the bag flap projecting from the folding flaps of the closed folding device. Furthermore, it is proposed that a take-over device can be moved horizontally relative to the fixing device and thus, in respect of height, is arranged underneath the fixing device in such a way that it is able to clamp the flat bag flap released by the folding device underneath the fixing device by means of clamping strips. Furthermore, it is proposed that the clamping strips of the take-over device comprise sealing means, especially a welding device.

[0013] Preferred embodiments of the invention are illustrated in the drawings and will be described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a side elevation view in a first end position of a first embodiment of this invention with a single filling sleeve.

[0015]FIG. 2 is a side elevation view of the device of FIG. 1 illustrated in a second end position.

[0016]FIG. 3 is a side elevation of a second embodiment of this invention with two filling sleeves in one of the two possible end positions.

[0017]FIG. 4 is an end view with details of the folding device in a closing position of the device according to FIGS. 1 to 3.

[0018]FIG. 5a is an end view of the device according to FIG. 4 with details of the closing device in the starting position.

[0019]FIG. 5b is a plan view of the device of FIG. 5a.

[0020]FIG. 6a is a side view illustrating details of the closing device in the closing position.

[0021]FIG. 6b is a plan view (one half) of the device of FIG. 6a in the closing position.

[0022]FIG. 6c is an end view of the device of FIG. 6a in the closing position.

[0023]FIG. 6d is an end view of the device of FIG. 6a in an intermediate position.

[0024]FIG. 7a is a side elevation cut out view of a third embodiment of this invention with one single filling sleeve.

[0025]FIG. 7b is a side view with details of the folding device and the spreading device.

[0026]FIG. 7c is a plan view with details of the spreading device.

[0027]FIG. 8a is a detailed side view illustrating the fixing device according to FIG. 7a with a ventilation unit and a take-over device.

[0028]FIG. 8b is an end view of the device of FIG. 8a.

[0029]FIG. 8c is a detail in a vertical section of the device of FIG. 8a.

[0030]FIG. 8d is a detail in a horizontal section of the device of FIG. 8a.

DETAILED DESCRIPTION OF THE INVENTION

[0031]FIG. 1 shows a device for filling bags with bulk material and for closing the filled bags in accordance with the invention in a first embodiment. A machine rack 11 and a switch cabinet 12 are arranged therein on the right. On the rack 11 there is fixed a dispensing device 13 comprising a lower dispensing cone portion 14. The dispensing cone 14 dispenses into a filling cone 15 which is movable in the horizontal direction in the drawing plane in a bag transporting direction and which is shown in a first one of its two end positions P1. The left-hand delimitation of the filling cone 15 aperture is flush with the left-hand delimitation of the dispensing cone 14 exit. The filling cone 15 is followed by a filling sleeve 16 which is screwed to the filling cone 15 and which, through the open sleeve exit, dispenses downwardly bulk material measured by the dispensing device 13 and sliding downwardly through the cones 14 and 15. Dashed lines indicate a bag in a first bag position S1, which bag is clamped to the filling sleeve 16. The above-mentioned direction of movement in the drawing plane from right to left represents the bag transporting direction. At the lower end, the bag in the bag position S1 is held by claws 17′ where it is prevented from swinging and is held in the required position during the filling operation. The bag can be slipped on to the filling sleeve 16 by means of a slipping-on device which is not shown in greater detail, but of which there are shown end portions of a pair of slip-on blades. The bag is held at the filling sleeve 16 by means of a bag clamping device 19 of which there is shown a bag clamp 39 acting on the front sleeve face. For simplifying purposes, the actuating means for the bag clamp 39 are not shown.

[0032] At a horizontal distance x1 from the filling sleeve 16, there is shown, in a starting position P2, a bag flap folding device 20 whose design and function will be explained later with reference to individual illustrations. The distance x1 refers to the centers of the devices 19 and 20. In a centered position above the folding device 20, there can be seen a side fold forming device 21 which can be lowered on to a bag in a second bag position S2 by means of an actuating cylinder 42. The side fold forming device 21 comprises two side fold forming blades which can be pivoted towards each other in the drawing plane and by means of which the side folds of a bag positioned in the second bag position S2 which side folds are located in the side faces positioned at the front and rear in the bag transporting direction can be folded inwardly prior to the bag flap being folded. The side fold forming blades 41 are shown in thin lines and are illustrated in an opened condition in an upper starting position and pivoted inwardly in a lower folded position. The center of the side fold forming device 21 coincides with the center of the folding device 20.

[0033] Underneath the folding device 20, there is arranged a depositing and vibrating table 23 for depositing a bag after it has been released by the filling sleeve 16, so that it assumes the second bag position S2 shown in dashed lines. The folding device 20 is associated with further claws 17″ which hold a bag in the required position while it is being deposited and vibrated and while the bag flap is being folded. At a horizontal distance x2 from the folding device 20, which horizontal distance x2 corresponds to the distance x1, there are provided a fold fixing device 25 and a take-over and sealing device 26 in a starting position P3, with this distance referring to the respective centers of the devices. Underneath the fold fixing device 25, there is located the start of a transport belt 24 which continues towards the left in the bag transporting direction. Dashed lines show a bag in a third bag position S3 at the beginning of the transport belt 24. Underneath the take-over and sealing device 26, and associated therewith, there are provided further claws 17′″ which support and hold the bag in its required condition. Whereas the fixing device 25 is firmly arranged at the rack 11 by means of a carrier 27, the remaining and subsequently mentioned details are horizontally movable relative to the rack 11. The filling cone 15, the filling sleeve 16, the side fold forming device 21, the folding device 20, the take-over and sealing device 26 and said claws 17′, 17″, 17′″ are connected to one another by a frame 28 which, in turn, is attached to a horizontally movable slide 30 in the rack 11. The claws 17 are connected to one another by a carrier 29 which is attached to the frame 28 via vertical arms 43. The slide 30 is driven via a crank drive 31 by an electric motor 32. The electric motor 32 acts via a belt drive 33 on a crank arm 34. The crank arm 34 then acts via a connecting rod 35 on the slide 30 which runs on guiding means 36. The travel of the slide 30 between the two extreme positions corresponds to the distance x1, x2 between the devices.

[0034]FIG. 2 shows the device according to FIG. 1 with the filling cone 15 in its second end position P2. The illustration is broken off on the right; for simplifying reasons, the side fold forming device 21 and the folding device 20 are not shown. Nevertheless, reference will be made to their position P3. These devices 19, 20, 21, 26 which can be moved by the slide 30 have been displaced towards the left by the amount x1, x2. First of all, this means that the filling cone 15 has been displaced relative to the dispensing device 13 (not shown) to such an extent that the right-hand delimitation of the filling cone 15 aperture is flush with the right-hand delimitation of the dispensing cone 13 exit. During the entire movement from the first end position P1 into the second end position P2, the two cones 14, 15 are in an open connection relative to one another. As a result of the movement of the filling cone 15 from position P1 into position P2, the bag suspended from the filling sleeve 16 has moved from the position previously referred to as S1 into the position describes as S2 in which the bag is still held at the filling sleeve 16 by means of the clamping device 19. Thereafter, with the clamping device having been opened, the bag is deposited into position S2 on the vibrating table 23. In the course of this process, the claws 17′ guide the bag and prevent it from falling over. The filling sleeve 16 is shown to be provided with an actuating cylinder 40 for actuating the clamping device 19. In the course of the displacement by the bag transport travel x1, x2, the bag which was previously in position S2 is, substantially, displaced by the claws 17″ into position S3, with the bag folding device 20 and the side fold forming device 21 (not shown) having followed the travel of the claws 17″ and with the bag folding device 20 having contributed towards the transport of the bags. The bag has been slid from the vibrating table 23 onto the start of the conveyor belt 24. In the process, the folded bag flap has been slid into the fixing device 25 which consists of two pairs of clamps 66 and 67, which is opened prior to the bag being slid-in, and which subsequently fixes the upper edges of the bag flap and which subsequently permits the bag folding device to be re-opened, without the folded bag flap opening up.

[0035] By means of the claws 17′″, a bag previously held by the take-over and sealing device 26 has been moved by the transport distance x3 from bag position S3 into bag position S4 in which it is released by the take-over device 26 for the purpose of being released to be transported further. The conveyor belt 24 can continue to be moved synchronously by the bag transport distance x1, x2, x3. If the bag has not yet been sealed by the take-over device, it can be drawn into a subsequent sealing device. The take-over and sealing device 26 opens its clamping jaws 37 actuated by the actuating cylinder 49 in order to release the bag. After, in the hand-over position illustrated here, the bag clamping device 19 in position P2 has been opened and the folding device 20 has been opened in position P3. The side fold forming device 21 has been returned into its upper position with the blades 41 being in an open condition. The take-over and sealing device 26 in position P4 has opened its clamping jaws 37 and after the claws 17 have been opened, the slide 30 with the carriers 28, 29 can be returned into the starting position according to FIG. 1 by the distance x1, x2, x3. In the meantime, one bag in the region of its unopened bag flap, which bag has already been folded, but not yet sealed, continues to be held in a closed condition in position S3 by the fixing device 25.

[0036] The upper end of the rack 11 is provided with a suction ventilator which is optionally connected to the bag flap folding device and optionally to a ventilation device to be described later.

[0037]FIG. 3 illustrates a second embodiment of this invention which has a largely symmetric design and in which bags can be filled and alternately conveyed in two opposed bag conveying directions located in the drawing place. Identical details have been given the same reference numbers as in FIGS. 1 and 2. To that extent, reference is made to said Figures. In the center of a rack 11, there is arranged one dispensing device 13 with a dispensing cone 14. Again, there is provided only one crank drive 31 with a motor 32 which acts on a slide 30 to which there is secured a frame 28. Of all the remaining elements of the device as the same as described for FIGS. 1 and 2, with the exception of the switch cabinet which is arranged elsewhere and is not visible. Two cabinets are provided and are arranged symmetrically with reference to a central plane E of the rack 11. The respective details, while having the same reference numbers, are differentiated by the addition of ′ and ″. For illustrative reasons, only the folding device 20′, but not the folding device 20″ is shown in the drawing and does not change the above-mentioned situation. The filling cones 15′ and 15″ with their attached filling sleeves 16′ and 16″ are arranged directly side by side, with the filling cone 15′ in its first end position P1′ being arranged in accordance with the filling sleeve 15 in FIG. 1 and with the filling cone 15″ in its second end position P2″ being arranged substantially analogously to the second end position of the filling cone 15 in FIG. 2. The lower exit cross-section of the dispensing cone 14 corresponds to the entry or aperture cross-section of the fillings cones 15′, 15″, in this case, too. The operation of filling a bag can still be continued after the first end position P1′, P2″ of the respective cone has been reached until the filling cone 15′, 15″ has been moved by the distance x1 to the left or right into its second end position P2′. P2″. In this process, the respective other filling cone is moved from its second end position P2′, P2″ into the first end position P1′, P1″ underneath the dispensing cone 14. If one takes into account that the process of emptying the dispensing cone 14 into one of the filling cones takes place relatively quickly relative to filling a bag suspended from the filling sleeve, this is completely analogous to the embodiment according to FIGS. 1 and 2. As a result, the filling speed can be increased considerably. While the bags in the bag positions S2″, S3″ and S4″ are filled and released respectively, further bags can be filled, folded-in, taken over and sealed in bag positions S1′, S2′, S3′. In consequence, the filling performance can be improved considerably.

[0038] The device marked ′ in FIG. 3 functions exactly like the device according to FIGS. 1 and 2 and transports bags in a first bag transporting direction R₁ towards the left. The device marked ″ functions analogously, but is offset by half an operating phase and transports the bags towards the right in the second bag transporting direction R₂.

[0039]FIG. 4 shows a device according to FIGS. 1 to 3 in a cross-sectional view, with only a selection of functional parts being illustrated inside the rack 11. A filling cone 15 with a flanged-on filling sleeve 16 is inserted into a slide 30 which can be moved perpendicularly to the drawing place on a pair of guiding bars 36 firmly incorporated into the rack 11. The frame 28 is connected to the slide 30. The following elements are articulated either directly or via further connecting carriers at the frame structure: a bag clamp 39 of the clamping device 19 laterally acting on the filling sleeve has to be actuated via a plurality of levers by the actuating cylinder 40 in such a way that the side walls of a bag which has been slipped on to the filling sleeve 16 can be clamped on to the filling sleeve 16 or released thereby. The releasing position is indicated by thin lines.

[0040] On its opposite side, the assembly consisting of the bag clamp 39 and the actuating cylinder 40 has a symmetrically arranged counter-part which, for simplifying reasons, has not been shown. Part of the vibrating table 23 is shown underneath the filling sleeve 16. A bag deposited on the vibrating table after the bag clamp 39 has been released can be held in position and fixed by the claws 17. The plurality of claws 17 is attached to the carriers 29 which, via guiding means in the form of a parallelogram, can be transferred by arms 43 and bars 44 from a holding position into a releasing position indicated by thin lines. The arms 43 are actuated directly by actuating cylinders 45 which rotate a rotatably supported lever plate 47 at which there are articulated connecting rods 46 which act on the upper free ends of the arms 43. By means of the lever plate it is thus possible to generate a high force ratio between the actuating cylinders 45 and the connecting rods 46. The take-over and sealing device 26 is attached via a carrier structure 48 which is connected to the frame 28, with the clamping strips 37 of the device 26, which clamping strips 37 attached to a pivot arm 38, are actuated by actuating cylinders 49. The clamping strips 37 can comprise welding jaws so that the bag flaps of bags consisting of a thermoplastic material can be welded thereby. Each of the details shown has a symmetric counter-part which, for the purpose of simplifying the illustration, has not been shown. Controllable fixing clamps 66, 67 are attached to the carrier 27 which is firmly arranged on the rack 11. After a bag has been transferred from the bag position S2 into the bag position S3, the fixing clamps 66, 67 fix the bag flap, which is doubled up at the top before the folding device 20 is opened and returned until the simultaneously approaching take-over and sealing device 26 takes over the doubled-up bag flap underneath the fixing clamps 66, 67.

[0041]FIG. 5 is a plan view of the rack according to FIG. 4 and illustrates some of the details which, for the sake of simplifying an illustration, had not been shown previously. In particular, this applies to a bag spreading device 22 which is articulated at the arms 43 which, in turn, are pivotably attached inside the structure of the frame 28. The movable parts of the device 22 comprise lifting bars 60 which can be moved by lifting cylinders 61 from a starting position indicated by thin lines into an engaged position indicated by continuous lines. At the lifting bars 60 there are arranged spreading arms 62 which comprise threaded-on , angled spreading fingers 63. The spreading fingers 63 articulated at spreading arms 62 are able to enter, from the top, the bag aperture of the bag deposited on the table 23. As can be seen in the plan view, the spreading arms 62 can be moved from a moving-in position indicated by thin lines into a spreading position indicated by continuous lines in which the spreading fingers 63 move away from one another as far as possible and in which the bag is opened up into the greatest possible, in this case square, cross-section with tensioned side walls. The spreading arms 62 are actuated by actuating cylinders 64, 65. It can be seen that on each side, the spreading arms 62 and spreading fingers 63 are provided in pairs. The folding device 20 positioned underneath the spreading device 22 is shown in its starting position in which the folding flaps 50 rest perpendicularly against the tensioned side walls.

[0042]FIG. 6 shows an inventive folding device 20 which comprises pairs of symmetric details which, by means of base plates 55, are secured to the free ends of the previously mentioned arms 43. This device comprises folding flaps 50 with box-shaped suction pads 52. The suction pads 52 comprise a series of suction apertures 56 and rear vacuum sleeves 53. The folding flaps 50 can be pivoted by pivot cylinders 51 around horizontal pivot axes into three different positions. The side edges of the folding flaps 50 are each provided with clamps 54. Illustrations c and d, in dashed thin lines, each show a bag, with the base plates 55, together with the arms, having been moved into their inner positions. In both Figures, thin lines indicate the folding flaps 50 in their starting positions in which the suction pads 52, by means of the vacuum sleeves 53, have contacted in a planar way the tensioned side walls of the bag. In illustration d, the folding flaps 50 are shown in an intermediate position in which they hold the lateral bag walls so that they are inclined in a roof-like position relative to one another, with the clamps 54 still being open. As a result of the roof-like inclination of the first side walls, the second side walls between the suction pads, which second side walls are each provided with the side folds and are positioned in front of and behind the drawing plane, have slackened, so that the doubled-up perpendicular corner edges of the bag can be gripped by the clamps 54. The clamps 54 are actuated by actuating cylinders 57 which cause the clamps to contact the underside of the suction pads 52, which underside is provided with apertures 56.

[0043] As can be seen in illustration d, the bag flap clearly projects upwardly beyond the clamps 54. After the corner edges have been clamped in, the folding flaps 50 are moved into the closing position according to illustration c in which the folding flaps are positioned horizontally on the filled bag. before such a movement can take place, the side folds are first drawn inwardly by the above-mentioned side fold forming blades, so that the bag flap with inwardly drawn-in side fold regions comes to rest between contacting clamping plates 58 at the folding flaps 50 and projects beyond the latter by the edge region K. In this position, the projecting edge regions can be gripped by the above-described fixing clamps, whereupon the folding flaps 50 can be returned into the starting position indicated by thin lines, with the base plates 55 being pivoted away from the bag by means of the arms.

[0044] After the folding device 20 has been moved away against the bag transporting direction, the bag flap can be taken over underneath the region K by the take-over and sealing device. This intermediate position is achieved by an intermediate position cylinder 59 which acts against the actuating cylinders 51 and which has to be relieved first before it allows the actuating cylinder 51 to be moved in again.

[0045]FIG. 7 illustrates in a cut-our a third embodiment of this invention for filling bags with bulk material and for closing the filled bags. Identical details have been given the same reference numbers as in FIG. 1. The filling cone 15 can be moved in a rack 11 in the horizontal direction in the drawing plane in a bag transporting direction and is shown in a first one of its two end positions P1. The filling cone 15 is followed by a filling sleeve 16 which is threaded on to the filling cone 15 and which dispenses bulk material downwardly through the open sleeve exit. Dashed thin lines show a bag clamped on to the filling sleeve 16 in a first bag position S1. The bag can be slipped on to the filling sleeve 16 by means of a slipping-on device which is not shown in detail but of which portions of a pair of slip-on blades are visible. The bag is held at the filling sleeve 16 by means of a bag clamping device 19 of which a bag clamp 39 acting on the front bag wall is visible. At its lower end, the bag is held as required in the bag position S1 by claws 17′ during the filling operation. At a horizontal distance x1 from the filling sleeve 16, in the starting position P1 of same, there is arranged a bag flap folding device 20 in its starting position P2. The distance x1 refers to the centers of the devices 19, 20. Centrally above the folding device 20, there is arranged a side fold forming device 21 which can be lowered on to a bag in a second bag position S2 by means of an actuating cylinder 42 and which comprises the two side fold forming blades 41 which can be pivoted against each other in the drawing plane and by means of which the side folds of a bag in the second bag position S2 can be formed inwardly prior to the bag flaps being folded-in. The side fold forming blades 41 are shown in an open condition in an upper starting position and pivoted inwardly in a lower folding position. The center of the side fold forming device 21 corresponds to the center of the folding device 20.

[0046] A bag spreading device 22 is associated with the side fold forming device 21. The movable parts of the spreading device 22 comprise spreading fingers 63 which are articulated at spreading arms 62 and which are able to reach from above into the bag aperture of a deposited bag in the bag position P2. The spreading arms 62 can be moved from an upper moving-in position indicated by continuous lines into a lower spreading position which is indicated by thin lines, in which the spreading fingers 63 move away from one another as far as possible, as a result of which the bag is opened and tensioned into the greatest possible cross-section with tensioned side walls. The movement of the spreading arms 62 is generated by actuating cylinders. It can be seen that the spreading fingers are always provided in pairs.

[0047] A folding device 20 positioned underneath the spreading device 22 is shown in its closing position in which the folding flaps which, in this case, also comprise suction pads which are positioned horizontally on the folded-in side walls of the bag. The folding flaps 50 can be pivoted around horizontal pivot axes by pivot cylinders 51. Thin lines indicate the folding flaps 50 in a starting position in which the folding flaps have contacted the tensioned side walls of the bag in a planar way. The folding device 20 is associated with further claws 17″ which hold the bag when it is being deposited and vibrated, and then the bag flap is being folded in the required form. At a horizontal distance x2 from the folding device 20, which corresponds to the distance x1, there is arranged a fold fixing device 25, with the distance referring to the respective centers of the devices. Dashed thin lines indicate a bag in its third bag position S3 at the beginning of a conveyor belt (not shown). Underneath the fold fixing device, there are provided further claws 17′″ which, with reference to the central axes, are associated with a take-over and sealing device 26 which is shown so as to be laterally drawn out. The take-over and sealing device 26 is shown in a take-over position P4 which, for illustrative reasons, has been drawn out of the overall illustration by the distance x3.

[0048] The fixing device 25 is firmly arranged on the rack 11 by a carrier 27. The remaining below-mentioned elements can be jointly moved horizontally with the frame 28 relative to the rack 11: the filling cone 15 and filling sleeve 16 from position P1 into position P2, the side fold forming device 21 and the folding device 20 from position P2 into position P3, the take-over and sealing device 26 from position P3 into position P4. These parts and the claws 17′, 17″, 17′″ are connected to one another via a frame 28 which, in turn, is attached to a horizontally movable slide 30 on the housing 11. The claws are connected to one another by carriers 29 which are attached to the frame 28 via vertical arms 43. The slide 30 is driven via a crank drive 31 by the electric motor 32 which, via a belt drive 33, acts on a crack arm 34. The crank arm 34 acts via a connecting rod 35 on the slide 30 which runs in guiding means 36.

[0049]FIG. 8 illustrates a fixing device 25 arranged at a fixed carrier 27 in position P3 and a take-over and welding device 26 arranged at the movable frame 28 in position P4. The fixing device comprises a pair of clamping strips 68 instead of the fixing clamps 66, 67 provided in other embodiments. Furthermore, the carrier 27 contains a ventilation probe 69 which can be moved in between formations of the closed pair of clamping strips 68. Finally, the pair of clamping strips is provided with inwardly opening and acting suction means 71. The pair of clamping strips is arranged pivotably via a pair of rotary bars 72 which at the same time serve to extract air, with actuation being effected by two actuating cylinders 73, 74 which are able to hold the pair of clamping strips 68 in a closing position, an intermediate position and an open position. It can be seen that the rotary beams 72 are provided with suction sleeves 75.

[0050] Furthermore, the fixing device 75 is provided with two pressure cylinders 76, 77 which are fixed to the carrier 27 and which, when the pair of clamping strips is open, are able to press on the upper edge of the folded bag flap in order to align the edge with the upper edge of the pair of clamping strips before the latter is closed. The take-over and fixing device 26 fixed to the frame 28 comprises clamping strips 37 which are positioned underneath the clamping strips 68, which are secured to the pivot arm 38 and which, after a bag in bag position S3 has been ventilated completely, can take over the bag and transfer it into bag position S4. After the bag folding device has been opened, first the pressure cylinders 76, 77 are actuated in bag position S3, whereupon they are withdrawn and the pair of clamping strips 68 is closed. After the respective walls of the bag flap have been sucked up by the suction means 71 in the clamping strips, the pair of clamping strips 68 is opened into the intermediate position and the vacuum probe 69 is slid in. Thereafter, the clamping strips 68 are closed and the residual air is extracted from the bag by the probe 69. Subsequently, the probe 69 can be withdrawn. Thereafter, the take-over device 26 moves from position P4 into position P3 in order to take over the folded and deaerated bag and optionally seal it and move it into bag position S4 for the purpose of it being transported further. 

I claim:
 1. A method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve connected to a filling cone and filled with a measured quantity of bulk material and wherein, for closing purposes, the bags, after having been filled, are folded-in at the bag flap in a bag flap folding device and, after having been closed, are gripped by a takeover device for the purpose of being transported further, wherein said filling sleeve during or after the operation of filling a suspended bag and the bag flap folding device during or after the operation of folding-in an attached bag are synchronously moved in a bag transporting direction at a fixed distance from a respective starting position by the amount of the distance x1 between the filling sleeve and the bag flap folding device into a respective hand-over position (P2, P3) wherein the respective bags are released by said filling sleeve and said bag flap folding device respectively, whereupon said filling sleeve and said bag flap folding device are returned synchronously at a fixed distance against the bag transporting direction into their respective starting positions (P1, P2).
 2. A method according to claim 1, wherein during said synchronous movement of said filling sleeve and of said bag flap folding device, said take-over device, for the purpose of further transport of a folded-in bag from a starting position (P3), which is at the same distance x1=x2 from the starting position (P2) of said bag flap folding device as is the latter in its starting position (P2) from the starting position (P1) of said filling sleeve, is moved in the bag transporting direction in the same phase into a releasing position (P4) wherein said take-over device releases the bag and is thereafter returned synchronously with said filling sleeve and said bag flap folding device into its starting position (P3).
 3. A method according to claim 2 wherein a bag is sealed in said take-over device.
 4. A method according to claim 2, wherein a bag is handed over by said takeover device into a subsequent sealing device.
 5. A method of filling bags with bulk material and of closing the filled bags, wherein, for filling purposes, the bags are suspended from a filling sleeve connected to a filling cone and filled with a measured quantity of bulk material and wherein, for closing purposes, the bags, after having been filled, are folded in at the bag flap in a bag flap folding device and, after having been closed, are gripped by a takeover device for the purpose of being transported further, wherein a first filling sleeve during or after the operation of filling a suspended bag and a first bag flap folding device during or after the operation of folding-in an attached bag are synchronously moved in a first bag transporting direction R1 at a fixed distance from a respective starting position (P1′, P2′) by the amount of the distance x1 between said first filling sleeve and said first bag flap folding device into a respective hand-over position (P2′, P3′) wherein the respective bags are released by said filling sleeve and said bag flap folding device (20′) respectively, whereupon said first filling sleeve and said first bag flap folding device (20′) are returned synchronously at the fixed distance against the first bag transporting direction R1 into their respective starting positions (P1′, P2′), while, at the same time, after the release of the respective bags, a second filling sleeve and a second bag flap folding device are moved synchronously at a fixed distance from one another by the amount of the distance x1 of said second filling sleeve from said second bag flap folding device into a respective starting position (P1″, P2″) where a bag slipped on to said filling sleeve (16″) is filled and where, respectively, a bag positioned in said bag flap folding device is folded-in, whereupon said second filling sleeve and said second bag flap folding device are returned synchronously in the second bag transporting direction R2 into their hand-over positions (P2″, P3″).
 6. A method according to claim 5, wherein during the synchronous movement of said first filling sleeve with said first bag flap folding device, a first take-over device for continuing the transport of a folded-in bag from a take-over position (P3′) which is at the same distance x2=x1 from the starting position (P2′) of said bag flap folding device as is the latter in its starting position (P2′) from the starting position (P1′) of said first filling sleeve (16′), is moved in the first bag transporting direction R1 in the same cycle into a releasing position (P4 ′) where it releases the bag and subsequently, synchronously with said first filling sleeve and said first bag flap folding device, is returned into its starting position (P3′), while simultaneously, during the synchronous movement of said second filling sleeve with said second bag flap folding device, a second take-over device for taking over a bag from a releasing position (P4″) is moved against the second bag transporting direction R2 in the same cycle into a take-over position (P3″) which is at the same distance x2=x1 from the starting position (P1″) of said second bag flap folding device as is the latter in its starting position (P2″) from the starting position (P1″) of said second filling sleeve and, after having taken over a bag, is returned synchronously with said second filling sleeve and said second bag flap folding device into its releasing position (P4″).
 7. A method according to claim 6, wherein bags are sealed in said first takeover device (26′) and in said second take-over device (26″).
 8. A method according to claim 6, wherein bags are transferred from said first take-over device and said second take-over device into subsequent first and second sealing devices.
 9. A method according to claim 1, wherein in a releasing position (P2), the bags are deposited by said filling sleeves.
 10. A method according to claim 5, wherein in a releasing position P2′, P2″, the bags are deposited by said filling sleeves.
 11. A method according to claim 1, wherein every possible position of said filling sleeves, said filling cones are in an open connection with an associated locally stationary dispensing device.
 12. A method according to claim 5, wherein every possible position of said filling sleeves, said filling cones are in an open connection with an associated locally stationary dispensing device.
 13. A device for filling bags with bulk material and for closing the filled bags, wherein there are provided a filling sleeve for attaching a bag, which filling sleeve is connected to a filling cone, a bag flap folding device for folding-in the bag flap of a bag and a take-over device for further transport of a bag after the folding-in operation, wherein said filling sleeve and said bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance x1 between said filling sleeve and said bag flap folding device between two respective starting positions (P1, P2) and two respective hand-over positions (P2, P3).
 14. A device according to claim 13, wherein said take-over device is movable between a starting position (P3), which is at the same distance x1=x2 from the starting position (P2) of said bag flap folding device as is the latter in its starting position (P2) from the starting position (P1) of said filling sleeve, and a releasing position (P4) in the same phase in the bag transporting direction and against the bag transporting direction as are said filling sleeve and said bag flap folding device.
 15. A device according to claim 14, wherein said take-over device comprises a sealing unit, especially a welding unit.
 16. A device according to claim 14, wherein a sealing unit follows said take-over device in the bag transporting direction.
 17. A device for filling bags with bulk material and for closing the filled bags, wherein there are provided a first filling sleeve for attaching a bag, which said first filling sleeve is connected to a filling cone, a first bag flap folding device for folding-in the bag flap of a bag, and a take-over device for further transport of a bag after the folding operation, wherein said first filling sleeve and said first bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance x1 between said first filling sleeve and said first bag flap folding device between two respective starting positions (P1′, P2′) and two respective hand-over positions (P2′, P3′) and wherein there are provided a second filling sleeve connected to a filling cone provided for attaching a bag, a second bag flap folding device for folding-in the bag flap of a bag and a second take-over device for further transport of a bag after having been folded, wherein said second filling sleeve and said second bag flap folding device are movable synchronously relative to one another at a fixed distance by the amount of the distance x1 between said second filling sleeve and said second bag flap folding device and synchronously with the former in the same respective direction between two respective hand-over positions (P2″, P3″) and two respective starting positions (P1″, P2″).
 18. A device according to claim 17, wherein said first take-over device is movable between a starting position (P3′), which is at the same distance x2=x1 from the starting position (P2′) of said first bag flap folding device as is the latter in its starting position (P2′) from the starting position (P1′) of said first filling sleeve, and a releasing position (P4 ′) in the same phase in the first bag transporting direction R₁ and against the first bag transporting direction R1 as are said first filling sleeve and said first bag flap folding device and wherein that a second take-over device is moveable between a starting position (P3″), which is at the same distance x2=x1 from the starting position (P2″) of a second bag flap folding device (20″) as is the latter in its starting position (P2″) from the starting position (P1″) of a second filling sleeve, and a releasing position (P4″) in the same phase in the second bag transporting direction R2 with the take-over devices being moveable in and against the second bag transporting direction R2 as are said second filling sleeve and said second bag flap folding device, with said take-over devices being movable in corresponding directions.
 19. A device according to claim 18, wherein said take-over devices each comprise a sealing unit, especially a welding unit.
 20. A device according to claim 18, wherein said take-over devices are each followed by a sealing unit in the bag transporting direction R1, R2.
 21. A bag flap folding device for open bags filled with a filling material, having a substantially rectangular cross-secion with two opposed first bag walls and two further opposed second bag walls, characterized by two folding flaps which, in a starting position, can be made to contact said first bag walls in a planar way and which can be pivoted around horizontal axes into a folding position in which they place the contacting first bag walls in a planar way substantially horizontally on the surface of the filing material, and with said bag flap projecting upwardly in a flat condition beyond the abutting end faces of said folding flaps.
 22. A device according to claim 21, wherein said folding flaps each carry suction pads which, if viewed in the starting position, are effective on the respective inner sides of said folding flaps.
 23. A device according to claim 22, wherein said folding flaps, together with said first side walls contacting one another in a planar way, can be stopped in an intermediate position in which they are inclined relative to one another in a roof-like way.
 24. A device according to claim 23, wherein a side fold forming device with two side fold forming blades which, in a starting position, are positioned at a distance outside the said tensioned second side walls and, in a side fold forming position, are positioned between said folding flaps in the intermediate position of same.
 25. A device according to claim 24, wherein said side fold forming device can be moved up and down.
 26. A device according to claim 24 wherein a fixing device which can be displaced horizontally relative to said bag flap folding device and which comprises clamping means which are able to fix the bag flap projecting from said folding flaps of said closed folding device by means of clamps.
 27. A device according to claim 26, wherein that a take-over device can be moved horizontally relative to said fixing device (25) and, in respect of height, is arranged underneath said fixing device (25) in such a way that it is able to clamp in the closed bag flap released by said folding device underneath said fixing device by means of clamping strips.
 28. A device according to claim 27, wherein a ventilation probe which can be moved into the fixed bag is connected to said fixing device.
 29. A device according to claim 28, wherein said fixing device comprises said clamping strips with suction means acting on the inside.
 30. A device according to claim 29, wherein said clamping strips of said takeover device comprise sealing means in the form of a welding device. 